1. Field of the Invention
This disclosure relates to an organic light emitting display (OLED) device and a method of manufacturing the same.
2. Discussion of the Related Art
Image display devices used for displaying a variety of information on a screen are one of the core technologies of the information and communication era. Such image display devices have been being developed to be thinner, lighter, and more portable, and furthermore to have a high performance. Actually, flat panel display devices are spotlighted in the display field due to their reduced weight and volume, well known disadvantages of cathode ray tubes (CRTs). The flat panel display devices include OLED devices, which display images by controlling the light emitting quantity of an organic light emission layer.
The OLED devices are self-illuminating display devices employing a thin light emission layer between electrodes. As such, the OLED devices can become thinner like a paper. Such OLED devices display images by emitting light through an encapsulated substrate. The encapsulated substrate includes a plurality of pixels arranged in a matrix shape and each configured with 3 colored (i.e., red, green and blue) sub-pixels, a cell driver array, and an organic light emission array.
In order to realize a variety of colors, the OLED device employs organic light emission layers, which are configured to emit red, green and blue lights, respectively. The organic light emission layer is interposed between two electrodes and used to form an organic light emission diode.
FIG. 1 is a cross-sectional view showing a seal region of the OLED device according to the related art.
As shown in FIG. 1, the OLED device is defined into an active area on which a plurality of pixels each including an organic light emission diode are arranged, and a pad area in which drive elements or power supply wirings are formed along the outline of the active area. A seal line area occupying edges of the pad area is included. In the seal line area, a sealant used for combining an array substrate provided with the organic light emission diodes with an upper substrate 18 is disposed.
The array substrate of the OLED device includes a buffer layer 11, a gate insulation layer 12 and an interlayer insulation film 13 stacked on a lower substrate 10. The array substrate further includes signal wirings 15 formed on the interlayer insulation film 13. The signal wirings 15 may be used for forming either the power supply wirings with a ground wiring or the drive elements. A reference number “20”, which is inserted in the drawing but not explained, indicates a bank layer. The bank layer 20 is used for not only defining the pixel regions within the active area but also forming the organic light emission diodes.
When the elements such as thin film transistors and the organic light emission diodes are formed on the lower substrate 10 as described above, a seal line 19 is formed along edges of the lower substrate in such a manner as to be across the signal wirings 15 (or the power wirings). Then, the upper and lower substrates 20 and 10 are combined with each other.
As shown in the drawing, a protective film, which had been formed on the signal wiring 15 is removed in order to reduce a number of processes. In other words, the protective film formation process is removed from the recent manufacturing process of an OLED device. However, due to this, a stained fault is generated in an area in which the seal line 19 and the signal wiring 15 are disposed.
FIG. 2 is a photographic view showing a stained fault, which is generated in the seal line area of the OLED device according to the related art. Referring to FIG. 2, it is seen that a stained fault is generated in an area A, which includes the seal line 19 formed on the signal wiring 15.
In other words, the stained fault which had been not generated in the case that the related art protective film is formed on the thin film transistor region of the active area and the signal wiring region of the pad area, is caused by removing the protective film formation process.
However, it is necessary to reduce a number of manufacturing processes by removing the protective film formation process, in order to provide high productivity and the cost reduction for the OLED device. Therefore, a new technology adapted to reduce a number of processes and prevent the stained fault must be developed.